1. Field of the Invention
The present invention relates to toothbrushes, and more particularly to toothbrushes in which the bristlemounting base thereof has one or more flexible elements pivotally coupled to the base.
2. History ofthe Prior Art
It is known to provide toothbrushes in which the bristle-mounting base thereof has one or more flexible elements which are pivotable relative to the base. An example of such a toothbrush is provided by U.S. Pat. No. 3,152,349 which was issued Oct. 13, 1964. The patent describes a toothbrush having a bristle-mounting base which includes a pair of tabs located in a central region of the base. The tabs are joined to the base by small segments of the plastic material which forms the base and the tabs so as to be pivotable relative to the base. Groups of relatively soft bristles are mounted on the base itself, while groups of relatively stiff bristles are mounted on the toothbrush tabs. During brushing, the softer outer groups of bristles mounted on the base gently brush the gums and adjacent portions of the teeth while the stiffer bristle groups brush and cleanse the more durable chewing surfaces of the teeth. The adjustable tabs pivot as necessary relative to the base of the toothbrush so that the stiffer bristle groups mounted on the tabs can conform to and better follow the contours of the chewing surfaces of the teeth during the brushing action.
Toothbrushes of the type described in previously referred to U.S. Pat. No. 3,152,349 have been found to be advantageous over more conventional toothbrush designs. Such brushes have been found to provide very thorough cleansing action of the teeth and particularly the chewing surfaces thereof while at the same time cleansing the gums and adjacent portions of the teeth in gentle, non-harmful fashion. However, such toothbrush design is not without its disadvantages. The tabs are joined to the base of the toothbrush by relatively thin segments of the plastic material forming both the base and the tabs to provide for pivoting action of the tabs relative to the base. The thin plastic segments which form hinges between the tabs and the base tend to fatigue and lose their "memory" with continued use of the toothbrush. The tabs fail to return to a neutral, non-pivoting position within the base, and brushing action is impaired. Eventually, the thin plastic segments becomes so weak that the tabs may break off from the base. This seriously limits the usefulness of the brush. Moreover, breaking off of the tabs on the base of the toothbrush usually occurs during brushing, with the attendant danger that the broken tab and included bristles will be swallowed.
Accordingly, it would be desirable to provide a toothbrush of the type having one or more flexible, bristle-mounting tabs or other elements in which the hinging action between the tabs and the base is improved and in which the possibility of the tabs breaking off of the base is greatly minimized or eliminated.